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I recently went through the handbook in a '09 BMW 330i E92 and it did recommend using only 'premium' fuel with minimum RON98. Something about the fact that it has knocking sensors so the engine runs a lot better with the premium fuel.
You mean 'knock' sensors. They don't mean the engine runs better on 'premium' fuel, they allow ignition timing to be advanced dynamically (which can be used as a mechanism for increasing power or reshaping the power/torque delivery curves, decreasing fuel consumption, improving emissions) to the point of pre-ignition.
A knock sensor detects the pre-ignition state ('knock') and retards the ignition timing to prevent it. Since fuel with a higher octane rating resists pre-ignition better, a knock sensor or knock sensors allow the ECU to adapt to different fuel characteristics, ensuring it can run optimally whatever fuel you chuck in the tank (within the allowable parameters of the ignition and fuelling maps, of course).
Some vehicles will be mapped to produce the same power whatever you fuel them with, some will be mapped to produce stated power using 97RON, some using 99RON, etc. Depending on how they're mapped, you may or may not see the power output change to meet, exceed, or fall short of expected (stated) values.0 -
BeenThroughItAll wrote: »You mean 'knock' sensors. They don't mean the engine runs better on 'premium' fuel, they allow ignition timing to be advanced dynamically (which can be used as a mechanism for increasing power or reshaping the power/torque delivery curves, decreasing fuel consumption, improving emissions) to the point of pre-ignition.
A knock sensor detects the pre-ignition state ('knock') and retards the ignition timing to prevent it. Since fuel with a higher octane rating resists pre-ignition better, a knock sensor or knock sensors allow the ECU to adapt to different fuel characteristics, ensuring it can run optimally whatever fuel you chuck in the tank (within the allowable parameters of the ignition and fuelling maps, of course).
Some vehicles will be mapped to produce the same power whatever you fuel them with, some will be mapped to produce stated power using 97RON, some using 99RON, etc. Depending on how they're mapped, you may or may not see the power output change to meet, exceed, or fall short of expected (stated) values.
I agree entirely. There was a lot of chat on the VW forums about the humble Golf 1.8T (mk IV) being built for 98 RON. It didn't have a problem running with 95 and did seem to drive better with premium - but that could have been just my perception. Without testing the same brand 95 vs 97 from the same forecourt, (and accepting that the fuels are different by refinement, rather than one being a better version of the other) this is just theory. And of course it was unleaded and not diesel.0 -
BeenThroughItAll wrote: »You mean 'knock' sensors. They don't mean the engine runs better on 'premium' fuel, they allow ignition timing to be advanced dynamically (which can be used as a mechanism for increasing power or reshaping the power/torque delivery curves, decreasing fuel consumption, improving emissions) to the point of pre-ignition.
A knock sensor detects the pre-ignition state ('knock') and retards the ignition timing to prevent it. Since fuel with a higher octane rating resists pre-ignition better, a knock sensor or knock sensors allow the ECU to adapt to different fuel characteristics, ensuring it can run optimally whatever fuel you chuck in the tank (within the allowable parameters of the ignition and fuelling maps, of course).
Some vehicles will be mapped to produce the same power whatever you fuel them with, some will be mapped to produce stated power using 97RON, some using 99RON, etc. Depending on how they're mapped, you may or may not see the power output change to meet, exceed, or fall short of expected (stated) values.
great thanks0 -
The 370z is quite a rare beast here in Greater London. How does it compare to the E46 M3 or Z4M if you've ever driven the M's? Both have similar power outputs to the 370z with its NA S54 engine I believe. Can't think of too many direct rivals of this generation with NA engine...Porsche Cayman maybe?
We drove an E92 M3 prior to buying the 370z. The M3 was nicer to drive, though not £15,000 more nicer to drive which is what it would have cost for a comparable miles / year of M3.
Plus with the 370z you get a bespoke sports car, rather than one derived from another production model.
We previously had a 3.0Si Coupe Z4, and it was fantastic. Z4M was ruled out based on age.
Cayman again was another possibility, but you're up another £15,000-£20,000 on what we paid for the Z for a similar age / miles car.
Might look to a couple of year old M4 / Cayman next time, but surprised how much we liked the Z actually. Its quite amazing. Very pleased.0 -
Way off the OPs topic !0
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I've just got my first diesel car and a few people have recommended using BP Ultimate, has anyone got any opinions on whether it's worth the extra money.
My cab is a Mondeo bought at 65k and it is now on just shy of 270k and I have used, almost exclusively, ASDA fuel, as ASDA are almost always the cheapest.
So, just over 200k on, essentially, ASDA fuel.
No concerns in all those miles and still going strong.0
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